"Miss Yvonne is quite senior and I'm sure she has her way of pursuing her job, and perhaps it doesn't go down well with her superiors. She's entitled to express herself as an employee."

Company insiders attribute Ridley's sacking to her bold campaigning for more rights for journalists on the al-Jazeera English channel and website, based in Doha, Qatar.

Before her arrival, journalists on the news site were often working 12-hour shifts, six days a week, without overtime pay or time off in lieu.

A week before her dismissal, Ridley presided over the subscription of most internet journalists at al-Jazeera English to the National Union of Journalists in the UK.

It is the first branch of the union to open in the Middle East.

Ballout attributed the sacking to "conflicting points of view", rejecting suggestions that Ridley was sacked for securing more rights for journalists.

He also defended the al-Jazeera English manager, Abdalaziz al-Mahmoud, who took the decision to dismiss her.

"I'm sure any decisions taken by the management of the operation are well thought through," Ballout said.

The move to remove the most senior journalist on the al-Jazeera English team has raised serious questions about the viability of the service's ground-breaking experiment in English-language news.

The struggling start-up and self-proclaimed rival to the BBC has had a rocky start.

After a nine-month delay in launching, staff shortages and a management restructure, al-Jazeera English went live in September to widespread accusations of bias in its coverage.

It was forced to withdraw some items following criticism from the White House and it is rumoured US pressure contributed to Ridley's removal.

Al-Jazeera has already capitulated to the Bush administration several times in recent months.

The website removed cartoons that depicted the twin towers of the World Trade Centre as two giant petrol pumps.

Al-Jazeera also appointed a new director, who is one of the few Arab journalists to have interviewed the US administrator in Iraq, Paul Bremer.

A few days before her dismissal Ridley said that, although she had never expected to work on a website after 25 years in print journalism, the experience had given her "a new lease of life".

She said: "There's a new deadline every second and the feedback is instant.

"I've got no intention of leaving Doha. I have many friends in this region and am launching a book called Ticket to Paradise, a thriller with fictional characters involved in all sorts of dirty dealings, swinging from New York to the Middle East."